Laminate radiation collimator

Abstract

A collimator (21, 38, 38A) transmits intercepted X rays or the like along an array of predetermined spaced apart paths (22, 22A), which may be parallel or convergent, while absorbing intercepted radiation which is traveling in other directions. A laminated construction of the collimator provides for an extremely large number of very minute and closely spaced radiation passages (42, 42A) which may have a noncircular cross section to increase transmissivity. The laminated construction also reduces the amount of heavy and sometimes costly radiation absorbent material required in the collimator, enables precise control of the transmitted radiation paths and facilitates the establishing of a desired focal point for the paths. Photoetching techniques, including optical image reduction, are used in the manufacture of the collimator laminations. In some variations of the method, the radiation absorbent material is plated onto the laminations.

I claim: 
     
       1. A radiation collimator defining a plurality of spaced apart radiation transmissive paths separated by radiation absorbent regions for suppressing intercepted radiation other than intercepted radiation which is traveling along said plurality of paths, wherein said collimator is comprised of a plurality of sheets of material each extending across said plurality of paths, each of said sheets of material being formed of a lamination of radiation transmissive material having a lamination of radiation absorbent material on at least one surface, said lamination of radiation absorbent material of each of said sheets being transpierced by a plurality of spaced apart radiation transmissive passages, corresponding ones of said passages of each of said laminations of radiation absorbent material being aligned to establish said radiation transmissive paths of said collimator. 
     
     
       2. A radiation collimator as defined in claim 1 further including a plurality of radiation transmissive spacer laminations, said spacer laminations being alternated with said sheets of material. 
     
     
       3. A radiation collimator as defined in claim 1 wherein said laminations of radiation transmissive material are transparent to light. 
     
     
       4. A radiation collimator as defined in claim 1 wherein said passages on each individual one of said laminations of radiation absorbent material are of uniform size and spacing and are of polygonal cross-sectional configuration. 
     
     
       5. A radiation collimator as defined in claim 4 wherein said passages are of rectangular cross-sectional configuration. 
     
     
       6. A radiation collimator as defined in claim 4 wherein said passages of successive ones of said laminations of radiation absorbent material are of progressively diminishing cross-sectional area. 
     
     
       7. A radiation collimator as defined in claim 4 wherein said passages of successive ones of said laminations of radiation absorbent material are spaced progressively closer together at each successive one of said laminations of radiation absorbent material causing said radiation transmissive paths to be convergent towards a focal point. 
     
     
       8. A radiation collimator as defined in claim 7 further including a plurality of spacer laminations alternated with said sheets of material, said spacer laminations being formed of radiation transmissive material and having a predetermined thickness selected to establish a predetermined degree of convergence of said radiation transmissive paths of said collimator. 
     
     
       9. A radiation collimator comprising a plurality of spaced apart collimating laminations formed at least in part of radiation absorbent material, each of said collimating laminations having an array of spaced apart radiation transmissive passages through said radiation absorbent material, corresponding passages of successive ones of said collimating laminations being aligned to define a plurality of spaced apart radiation paths through said collimator, and a plurality of spacer laminations alternated with said collimating laminations along said radiation paths, said spacer laminations being flat sheets of radiation transmissive material extending in parallel relationship with said collimating laminations and being in contact therewith. 
     
     
       10. A radiation collimator as defined in claim 9 wherein said passages of each of said collimating laminations are similarly spaced apart to cause said radiation paths to be parallel. 
     
     
       11. A radiation collimator as defined in claim 9 wherein said passages are of uniform size and spacing on each individual one of said collimating laminations, and wherein said passages of successive ones of said collimating laminations are progressively closer together to cause said radiation paths to be convergent. 
     
     
       12. A radiation collimator as defined in claim 11 wherein said passages of said successive ones of said collimating laminations are of progressively diminishing cross-sectional area.